2 * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include <openssl/crypto.h>
12 #include <openssl/err.h>
13 #include <openssl/rand.h>
15 #include "internal/thread_once.h"
16 #include "internal/rand_int.h"
17 #include "internal/cryptlib_int.h"
20 * Support framework for NIST SP 800-90A DRBG
22 * See manual page RAND_DRBG(7) for a general overview.
24 * The OpenSSL model is to have new and free functions, and that new
25 * does all initialization. That is not the NIST model, which has
26 * instantiation and un-instantiate, and re-use within a new/free
27 * lifecycle. (No doubt this comes from the desire to support hardware
28 * DRBG, where allocation of resources on something like an HSM is
29 * a much bigger deal than just re-setting an allocated resource.)
33 * The three shared DRBG instances
35 * There are three shared DRBG instances: <master>, <public>, and <private>.
41 * Not used directly by the application, only for reseeding the two other
42 * DRBGs. It reseeds itself by pulling either randomness from os entropy
43 * sources or by consuming randomness which was added by RAND_add().
45 * The <master> DRBG is a global instance which is accessed concurrently by
46 * all threads. The necessary locking is managed automatically by its child
47 * DRBG instances during reseeding.
49 static RAND_DRBG
*master_drbg
;
53 * Used by default for generating random bytes using RAND_bytes().
55 * The <public> DRBG is thread-local, i.e., there is one instance per thread.
57 static CRYPTO_THREAD_LOCAL public_drbg
;
61 * Used by default for generating private keys using RAND_priv_bytes()
63 * The <private> DRBG is thread-local, i.e., there is one instance per thread.
65 static CRYPTO_THREAD_LOCAL private_drbg
;
69 /* NIST SP 800-90A DRBG recommends the use of a personalization string. */
70 static const char ossl_pers_string
[] = "OpenSSL NIST SP 800-90A DRBG";
72 static CRYPTO_ONCE rand_drbg_init
= CRYPTO_ONCE_STATIC_INIT
;
75 #define RAND_DRBG_TYPE_FLAGS ( \
76 RAND_DRBG_FLAG_MASTER | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
78 #define RAND_DRBG_TYPE_MASTER 0
79 #define RAND_DRBG_TYPE_PUBLIC 1
80 #define RAND_DRBG_TYPE_PRIVATE 2
83 static int rand_drbg_type
[3] = {
84 RAND_DRBG_TYPE
, /* Master */
85 RAND_DRBG_TYPE
, /* Public */
86 RAND_DRBG_TYPE
/* Private */
88 static unsigned int rand_drbg_flags
[3] = {
89 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_MASTER
, /* Master */
90 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_PUBLIC
, /* Public */
91 RAND_DRBG_FLAGS
| RAND_DRBG_FLAG_PRIVATE
/* Private */
94 static unsigned int master_reseed_interval
= MASTER_RESEED_INTERVAL
;
95 static unsigned int slave_reseed_interval
= SLAVE_RESEED_INTERVAL
;
97 static time_t master_reseed_time_interval
= MASTER_RESEED_TIME_INTERVAL
;
98 static time_t slave_reseed_time_interval
= SLAVE_RESEED_TIME_INTERVAL
;
100 /* A logical OR of all used DRBG flag bits (currently there is only one) */
101 static const unsigned int rand_drbg_used_flags
=
102 RAND_DRBG_FLAG_CTR_NO_DF
| RAND_DRBG_FLAG_HMAC
| RAND_DRBG_TYPE_FLAGS
;
105 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
, int drbg_type
);
107 static RAND_DRBG
*rand_drbg_new(int secure
,
112 static int is_ctr(int type
)
115 case NID_aes_128_ctr
:
116 case NID_aes_192_ctr
:
117 case NID_aes_256_ctr
:
124 static int is_digest(int type
)
145 * Set/initialize |drbg| to be of type |type|, with optional |flags|.
147 * If |type| and |flags| are zero, use the defaults
149 * Returns 1 on success, 0 on failure.
151 int RAND_DRBG_set(RAND_DRBG
*drbg
, int type
, unsigned int flags
)
155 if (type
== 0 && flags
== 0) {
156 type
= rand_drbg_type
[RAND_DRBG_TYPE_MASTER
];
157 flags
= rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
];
160 /* If set is called multiple times - clear the old one */
161 if (type
!= drbg
->type
&& drbg
->type
!= 0 && drbg
->meth
!= NULL
) {
162 drbg
->meth
->uninstantiate(drbg
);
165 drbg
->state
= DRBG_UNINITIALISED
;
170 /* Uninitialized; that's okay. */
172 } else if (is_ctr(type
)) {
173 ret
= drbg_ctr_init(drbg
);
174 } else if (is_digest(type
)) {
175 if (flags
& RAND_DRBG_FLAG_HMAC
)
176 ret
= drbg_hmac_init(drbg
);
178 ret
= drbg_hash_init(drbg
);
180 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
185 RANDerr(RAND_F_RAND_DRBG_SET
, RAND_R_ERROR_INITIALISING_DRBG
);
190 * Set/initialize default |type| and |flag| for new drbg instances.
192 * Returns 1 on success, 0 on failure.
194 int RAND_DRBG_set_defaults(int type
, unsigned int flags
)
197 if (!(is_digest(type
) || is_ctr(type
))) {
198 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_TYPE
);
202 if ((flags
& ~rand_drbg_used_flags
) != 0) {
203 RANDerr(RAND_F_RAND_DRBG_SET_DEFAULTS
, RAND_R_UNSUPPORTED_DRBG_FLAGS
);
207 all
= ((flags
& RAND_DRBG_TYPE_FLAGS
) == 0);
208 if (all
|| (flags
& RAND_DRBG_FLAG_MASTER
) != 0) {
209 rand_drbg_type
[RAND_DRBG_TYPE_MASTER
] = type
;
210 rand_drbg_flags
[RAND_DRBG_TYPE_MASTER
] = flags
| RAND_DRBG_FLAG_MASTER
;
212 if (all
|| (flags
& RAND_DRBG_FLAG_PUBLIC
) != 0) {
213 rand_drbg_type
[RAND_DRBG_TYPE_PUBLIC
] = type
;
214 rand_drbg_flags
[RAND_DRBG_TYPE_PUBLIC
] = flags
| RAND_DRBG_FLAG_PUBLIC
;
216 if (all
|| (flags
& RAND_DRBG_FLAG_PRIVATE
) != 0) {
217 rand_drbg_type
[RAND_DRBG_TYPE_PRIVATE
] = type
;
218 rand_drbg_flags
[RAND_DRBG_TYPE_PRIVATE
] = flags
| RAND_DRBG_FLAG_PRIVATE
;
225 * Allocate memory and initialize a new DRBG. The DRBG is allocated on
226 * the secure heap if |secure| is nonzero and the secure heap is enabled.
227 * The |parent|, if not NULL, will be used as random source for reseeding.
229 * Returns a pointer to the new DRBG instance on success, NULL on failure.
231 static RAND_DRBG
*rand_drbg_new(int secure
,
236 RAND_DRBG
*drbg
= secure
?
237 OPENSSL_secure_zalloc(sizeof(*drbg
)) : OPENSSL_zalloc(sizeof(*drbg
));
240 RANDerr(RAND_F_RAND_DRBG_NEW
, ERR_R_MALLOC_FAILURE
);
244 drbg
->secure
= secure
&& CRYPTO_secure_allocated(drbg
);
245 drbg
->fork_count
= rand_fork_count
;
246 drbg
->parent
= parent
;
248 if (parent
== NULL
) {
249 drbg
->get_entropy
= rand_drbg_get_entropy
;
250 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
251 #ifndef RAND_DRBG_GET_RANDOM_NONCE
252 drbg
->get_nonce
= rand_drbg_get_nonce
;
253 drbg
->cleanup_nonce
= rand_drbg_cleanup_nonce
;
256 drbg
->reseed_interval
= master_reseed_interval
;
257 drbg
->reseed_time_interval
= master_reseed_time_interval
;
259 drbg
->get_entropy
= rand_drbg_get_entropy
;
260 drbg
->cleanup_entropy
= rand_drbg_cleanup_entropy
;
262 * Do not provide nonce callbacks, the child DRBGs will
263 * obtain their nonce using random bits from the parent.
266 drbg
->reseed_interval
= slave_reseed_interval
;
267 drbg
->reseed_time_interval
= slave_reseed_time_interval
;
270 if (RAND_DRBG_set(drbg
, type
, flags
) == 0)
273 if (parent
!= NULL
) {
274 rand_drbg_lock(parent
);
275 if (drbg
->strength
> parent
->strength
) {
277 * We currently don't support the algorithm from NIST SP 800-90C
278 * 10.1.2 to use a weaker DRBG as source
280 rand_drbg_unlock(parent
);
281 RANDerr(RAND_F_RAND_DRBG_NEW
, RAND_R_PARENT_STRENGTH_TOO_WEAK
);
284 rand_drbg_unlock(parent
);
291 OPENSSL_secure_free(drbg
);
298 RAND_DRBG
*RAND_DRBG_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
300 return rand_drbg_new(0, type
, flags
, parent
);
303 RAND_DRBG
*RAND_DRBG_secure_new(int type
, unsigned int flags
, RAND_DRBG
*parent
)
305 return rand_drbg_new(1, type
, flags
, parent
);
309 * Uninstantiate |drbg| and free all memory.
311 void RAND_DRBG_free(RAND_DRBG
*drbg
)
316 if (drbg
->meth
!= NULL
)
317 drbg
->meth
->uninstantiate(drbg
);
318 CRYPTO_THREAD_lock_free(drbg
->lock
);
319 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG
, drbg
, &drbg
->ex_data
);
322 OPENSSL_secure_clear_free(drbg
, sizeof(*drbg
));
324 OPENSSL_clear_free(drbg
, sizeof(*drbg
));
328 * Instantiate |drbg|, after it has been initialized. Use |pers| and
329 * |perslen| as prediction-resistance input.
331 * Requires that drbg->lock is already locked for write, if non-null.
333 * Returns 1 on success, 0 on failure.
335 int RAND_DRBG_instantiate(RAND_DRBG
*drbg
,
336 const unsigned char *pers
, size_t perslen
)
338 unsigned char *nonce
= NULL
, *entropy
= NULL
;
339 size_t noncelen
= 0, entropylen
= 0;
340 size_t min_entropy
= drbg
->strength
;
341 size_t min_entropylen
= drbg
->min_entropylen
;
342 size_t max_entropylen
= drbg
->max_entropylen
;
344 if (perslen
> drbg
->max_perslen
) {
345 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
346 RAND_R_PERSONALISATION_STRING_TOO_LONG
);
350 if (drbg
->meth
== NULL
) {
351 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
352 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
356 if (drbg
->state
!= DRBG_UNINITIALISED
) {
357 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
358 drbg
->state
== DRBG_ERROR
? RAND_R_IN_ERROR_STATE
359 : RAND_R_ALREADY_INSTANTIATED
);
363 drbg
->state
= DRBG_ERROR
;
366 * NIST SP800-90Ar1 section 9.1 says you can combine getting the entropy
367 * and nonce in 1 call by increasing the entropy with 50% and increasing
368 * the minimum length to accomadate the length of the nonce.
369 * We do this in case a nonce is require and get_nonce is NULL.
371 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
== NULL
) {
372 min_entropy
+= drbg
->strength
/ 2;
373 min_entropylen
+= drbg
->min_noncelen
;
374 max_entropylen
+= drbg
->max_noncelen
;
377 if (drbg
->get_entropy
!= NULL
)
378 entropylen
= drbg
->get_entropy(drbg
, &entropy
, min_entropy
,
379 min_entropylen
, max_entropylen
, 0);
380 if (entropylen
< min_entropylen
381 || entropylen
> max_entropylen
) {
382 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
386 if (drbg
->min_noncelen
> 0 && drbg
->get_nonce
!= NULL
) {
387 noncelen
= drbg
->get_nonce(drbg
, &nonce
, drbg
->strength
/ 2,
388 drbg
->min_noncelen
, drbg
->max_noncelen
);
389 if (noncelen
< drbg
->min_noncelen
|| noncelen
> drbg
->max_noncelen
) {
390 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_RETRIEVING_NONCE
);
395 if (!drbg
->meth
->instantiate(drbg
, entropy
, entropylen
,
396 nonce
, noncelen
, pers
, perslen
)) {
397 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
, RAND_R_ERROR_INSTANTIATING_DRBG
);
401 drbg
->state
= DRBG_READY
;
402 drbg
->reseed_gen_counter
= 1;
403 drbg
->reseed_time
= time(NULL
);
404 if (drbg
->reseed_prop_counter
> 0) {
405 if (drbg
->parent
== NULL
)
406 drbg
->reseed_prop_counter
++;
408 drbg
->reseed_prop_counter
= drbg
->parent
->reseed_prop_counter
;
412 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
413 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
414 if (nonce
!= NULL
&& drbg
->cleanup_nonce
!= NULL
)
415 drbg
->cleanup_nonce(drbg
, nonce
, noncelen
);
416 if (drbg
->pool
!= NULL
) {
417 if (drbg
->state
== DRBG_READY
) {
418 RANDerr(RAND_F_RAND_DRBG_INSTANTIATE
,
419 RAND_R_ERROR_ENTROPY_POOL_WAS_IGNORED
);
420 drbg
->state
= DRBG_ERROR
;
422 rand_pool_free(drbg
->pool
);
425 if (drbg
->state
== DRBG_READY
)
431 * Uninstantiate |drbg|. Must be instantiated before it can be used.
433 * Requires that drbg->lock is already locked for write, if non-null.
435 * Returns 1 on success, 0 on failure.
437 int RAND_DRBG_uninstantiate(RAND_DRBG
*drbg
)
439 int index
= -1, type
, flags
;
440 if (drbg
->meth
== NULL
) {
441 RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE
,
442 RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED
);
446 /* Clear the entire drbg->ctr struct, then reset some important
447 * members of the drbg->ctr struct (e.g. keysize, df_ks) to their
450 drbg
->meth
->uninstantiate(drbg
);
452 /* The reset uses the default values for type and flags */
453 if (drbg
->flags
& RAND_DRBG_FLAG_MASTER
)
454 index
= RAND_DRBG_TYPE_MASTER
;
455 else if (drbg
->flags
& RAND_DRBG_FLAG_PRIVATE
)
456 index
= RAND_DRBG_TYPE_PRIVATE
;
457 else if (drbg
->flags
& RAND_DRBG_FLAG_PUBLIC
)
458 index
= RAND_DRBG_TYPE_PUBLIC
;
461 flags
= rand_drbg_flags
[index
];
462 type
= rand_drbg_type
[index
];
467 return RAND_DRBG_set(drbg
, type
, flags
);
471 * Reseed |drbg|, mixing in the specified data
473 * Requires that drbg->lock is already locked for write, if non-null.
475 * Returns 1 on success, 0 on failure.
477 int RAND_DRBG_reseed(RAND_DRBG
*drbg
,
478 const unsigned char *adin
, size_t adinlen
,
479 int prediction_resistance
)
481 unsigned char *entropy
= NULL
;
482 size_t entropylen
= 0;
484 if (drbg
->state
== DRBG_ERROR
) {
485 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_IN_ERROR_STATE
);
488 if (drbg
->state
== DRBG_UNINITIALISED
) {
489 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_NOT_INSTANTIATED
);
495 } else if (adinlen
> drbg
->max_adinlen
) {
496 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
500 drbg
->state
= DRBG_ERROR
;
501 if (drbg
->get_entropy
!= NULL
)
502 entropylen
= drbg
->get_entropy(drbg
, &entropy
, drbg
->strength
,
503 drbg
->min_entropylen
,
504 drbg
->max_entropylen
,
505 prediction_resistance
);
506 if (entropylen
< drbg
->min_entropylen
507 || entropylen
> drbg
->max_entropylen
) {
508 RANDerr(RAND_F_RAND_DRBG_RESEED
, RAND_R_ERROR_RETRIEVING_ENTROPY
);
512 if (!drbg
->meth
->reseed(drbg
, entropy
, entropylen
, adin
, adinlen
))
515 drbg
->state
= DRBG_READY
;
516 drbg
->reseed_gen_counter
= 1;
517 drbg
->reseed_time
= time(NULL
);
518 if (drbg
->reseed_prop_counter
> 0) {
519 if (drbg
->parent
== NULL
)
520 drbg
->reseed_prop_counter
++;
522 drbg
->reseed_prop_counter
= drbg
->parent
->reseed_prop_counter
;
526 if (entropy
!= NULL
&& drbg
->cleanup_entropy
!= NULL
)
527 drbg
->cleanup_entropy(drbg
, entropy
, entropylen
);
528 if (drbg
->state
== DRBG_READY
)
534 * Restart |drbg|, using the specified entropy or additional input
536 * Tries its best to get the drbg instantiated by all means,
537 * regardless of its current state.
539 * Optionally, a |buffer| of |len| random bytes can be passed,
540 * which is assumed to contain at least |entropy| bits of entropy.
542 * If |entropy| > 0, the buffer content is used as entropy input.
544 * If |entropy| == 0, the buffer content is used as additional input
546 * Returns 1 on success, 0 on failure.
548 * This function is used internally only.
550 int rand_drbg_restart(RAND_DRBG
*drbg
,
551 const unsigned char *buffer
, size_t len
, size_t entropy
)
554 const unsigned char *adin
= NULL
;
557 if (drbg
->pool
!= NULL
) {
558 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
559 drbg
->state
= DRBG_ERROR
;
560 rand_pool_free(drbg
->pool
);
565 if (buffer
!= NULL
) {
567 if (drbg
->max_entropylen
< len
) {
568 RANDerr(RAND_F_RAND_DRBG_RESTART
,
569 RAND_R_ENTROPY_INPUT_TOO_LONG
);
570 drbg
->state
= DRBG_ERROR
;
574 if (entropy
> 8 * len
) {
575 RANDerr(RAND_F_RAND_DRBG_RESTART
, RAND_R_ENTROPY_OUT_OF_RANGE
);
576 drbg
->state
= DRBG_ERROR
;
580 /* will be picked up by the rand_drbg_get_entropy() callback */
581 drbg
->pool
= rand_pool_attach(buffer
, len
, entropy
);
582 if (drbg
->pool
== NULL
)
585 if (drbg
->max_adinlen
< len
) {
586 RANDerr(RAND_F_RAND_DRBG_RESTART
,
587 RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
588 drbg
->state
= DRBG_ERROR
;
596 /* repair error state */
597 if (drbg
->state
== DRBG_ERROR
)
598 RAND_DRBG_uninstantiate(drbg
);
600 /* repair uninitialized state */
601 if (drbg
->state
== DRBG_UNINITIALISED
) {
602 /* reinstantiate drbg */
603 RAND_DRBG_instantiate(drbg
,
604 (const unsigned char *) ossl_pers_string
,
605 sizeof(ossl_pers_string
) - 1);
606 /* already reseeded. prevent second reseeding below */
607 reseeded
= (drbg
->state
== DRBG_READY
);
610 /* refresh current state if entropy or additional input has been provided */
611 if (drbg
->state
== DRBG_READY
) {
614 * mix in additional input without reseeding
616 * Similar to RAND_DRBG_reseed(), but the provided additional
617 * data |adin| is mixed into the current state without pulling
618 * entropy from the trusted entropy source using get_entropy().
619 * This is not a reseeding in the strict sense of NIST SP 800-90A.
621 drbg
->meth
->reseed(drbg
, adin
, adinlen
, NULL
, 0);
622 } else if (reseeded
== 0) {
623 /* do a full reseeding if it has not been done yet above */
624 RAND_DRBG_reseed(drbg
, NULL
, 0, 0);
628 /* check whether a given entropy pool was cleared properly during reseed */
629 if (drbg
->pool
!= NULL
) {
630 drbg
->state
= DRBG_ERROR
;
631 RANDerr(RAND_F_RAND_DRBG_RESTART
, ERR_R_INTERNAL_ERROR
);
632 rand_pool_free(drbg
->pool
);
637 return drbg
->state
== DRBG_READY
;
641 * Generate |outlen| bytes into the buffer at |out|. Reseed if we need
642 * to or if |prediction_resistance| is set. Additional input can be
643 * sent in |adin| and |adinlen|.
645 * Requires that drbg->lock is already locked for write, if non-null.
647 * Returns 1 on success, 0 on failure.
650 int RAND_DRBG_generate(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
,
651 int prediction_resistance
,
652 const unsigned char *adin
, size_t adinlen
)
654 int reseed_required
= 0;
656 if (drbg
->state
!= DRBG_READY
) {
657 /* try to recover from previous errors */
658 rand_drbg_restart(drbg
, NULL
, 0, 0);
660 if (drbg
->state
== DRBG_ERROR
) {
661 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_IN_ERROR_STATE
);
664 if (drbg
->state
== DRBG_UNINITIALISED
) {
665 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_NOT_INSTANTIATED
);
670 if (outlen
> drbg
->max_request
) {
671 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_REQUEST_TOO_LARGE_FOR_DRBG
);
674 if (adinlen
> drbg
->max_adinlen
) {
675 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_ADDITIONAL_INPUT_TOO_LONG
);
679 if (drbg
->fork_count
!= rand_fork_count
) {
680 drbg
->fork_count
= rand_fork_count
;
684 if (drbg
->reseed_interval
> 0) {
685 if (drbg
->reseed_gen_counter
> drbg
->reseed_interval
)
688 if (drbg
->reseed_time_interval
> 0) {
689 time_t now
= time(NULL
);
690 if (now
< drbg
->reseed_time
691 || now
- drbg
->reseed_time
>= drbg
->reseed_time_interval
)
694 if (drbg
->reseed_prop_counter
> 0 && drbg
->parent
!= NULL
) {
695 if (drbg
->reseed_prop_counter
!= drbg
->parent
->reseed_prop_counter
)
699 if (reseed_required
|| prediction_resistance
) {
700 if (!RAND_DRBG_reseed(drbg
, adin
, adinlen
, prediction_resistance
)) {
701 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_RESEED_ERROR
);
708 if (!drbg
->meth
->generate(drbg
, out
, outlen
, adin
, adinlen
)) {
709 drbg
->state
= DRBG_ERROR
;
710 RANDerr(RAND_F_RAND_DRBG_GENERATE
, RAND_R_GENERATE_ERROR
);
714 drbg
->reseed_gen_counter
++;
720 * Generates |outlen| random bytes and stores them in |out|. It will
721 * using the given |drbg| to generate the bytes.
723 * Requires that drbg->lock is already locked for write, if non-null.
725 * Returns 1 on success 0 on failure.
727 int RAND_DRBG_bytes(RAND_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
729 unsigned char *additional
= NULL
;
730 size_t additional_len
;
734 additional_len
= rand_drbg_get_additional_data(&additional
, drbg
->max_adinlen
);
736 for ( ; outlen
> 0; outlen
-= chunk
, out
+= chunk
) {
738 if (chunk
> drbg
->max_request
)
739 chunk
= drbg
->max_request
;
740 ret
= RAND_DRBG_generate(drbg
, out
, chunk
, 0, additional
, additional_len
);
747 if (additional_len
!= 0)
748 OPENSSL_secure_clear_free(additional
, additional_len
);
754 * Set the RAND_DRBG callbacks for obtaining entropy and nonce.
756 * Setting the callbacks is allowed only if the drbg has not been
757 * initialized yet. Otherwise, the operation will fail.
759 * Returns 1 on success, 0 on failure.
761 int RAND_DRBG_set_callbacks(RAND_DRBG
*drbg
,
762 RAND_DRBG_get_entropy_fn get_entropy
,
763 RAND_DRBG_cleanup_entropy_fn cleanup_entropy
,
764 RAND_DRBG_get_nonce_fn get_nonce
,
765 RAND_DRBG_cleanup_nonce_fn cleanup_nonce
)
767 if (drbg
->state
!= DRBG_UNINITIALISED
)
769 drbg
->get_entropy
= get_entropy
;
770 drbg
->cleanup_entropy
= cleanup_entropy
;
771 drbg
->get_nonce
= get_nonce
;
772 drbg
->cleanup_nonce
= cleanup_nonce
;
777 * Set the reseed interval.
779 * The drbg will reseed automatically whenever the number of generate
780 * requests exceeds the given reseed interval. If the reseed interval
781 * is 0, then this feature is disabled.
783 * Returns 1 on success, 0 on failure.
785 int RAND_DRBG_set_reseed_interval(RAND_DRBG
*drbg
, unsigned int interval
)
787 if (interval
> MAX_RESEED_INTERVAL
)
789 drbg
->reseed_interval
= interval
;
794 * Set the reseed time interval.
796 * The drbg will reseed automatically whenever the time elapsed since
797 * the last reseeding exceeds the given reseed time interval. For safety,
798 * a reseeding will also occur if the clock has been reset to a smaller
801 * Returns 1 on success, 0 on failure.
803 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG
*drbg
, time_t interval
)
805 if (interval
> MAX_RESEED_TIME_INTERVAL
)
807 drbg
->reseed_time_interval
= interval
;
812 * Set the default values for reseed (time) intervals of new DRBG instances
814 * The default values can be set independently for master DRBG instances
815 * (without a parent) and slave DRBG instances (with parent).
817 * Returns 1 on success, 0 on failure.
820 int RAND_DRBG_set_reseed_defaults(
821 unsigned int _master_reseed_interval
,
822 unsigned int _slave_reseed_interval
,
823 time_t _master_reseed_time_interval
,
824 time_t _slave_reseed_time_interval
827 if (_master_reseed_interval
> MAX_RESEED_INTERVAL
828 || _slave_reseed_interval
> MAX_RESEED_INTERVAL
)
831 if (_master_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
832 || _slave_reseed_time_interval
> MAX_RESEED_TIME_INTERVAL
)
835 master_reseed_interval
= _master_reseed_interval
;
836 slave_reseed_interval
= _slave_reseed_interval
;
838 master_reseed_time_interval
= _master_reseed_time_interval
;
839 slave_reseed_time_interval
= _slave_reseed_time_interval
;
845 * Locks the given drbg. Locking a drbg which does not have locking
846 * enabled is considered a successful no-op.
848 * Returns 1 on success, 0 on failure.
850 int rand_drbg_lock(RAND_DRBG
*drbg
)
852 if (drbg
->lock
!= NULL
)
853 return CRYPTO_THREAD_write_lock(drbg
->lock
);
859 * Unlocks the given drbg. Unlocking a drbg which does not have locking
860 * enabled is considered a successful no-op.
862 * Returns 1 on success, 0 on failure.
864 int rand_drbg_unlock(RAND_DRBG
*drbg
)
866 if (drbg
->lock
!= NULL
)
867 return CRYPTO_THREAD_unlock(drbg
->lock
);
873 * Enables locking for the given drbg
875 * Locking can only be enabled if the random generator
876 * is in the uninitialized state.
878 * Returns 1 on success, 0 on failure.
880 int rand_drbg_enable_locking(RAND_DRBG
*drbg
)
882 if (drbg
->state
!= DRBG_UNINITIALISED
) {
883 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
884 RAND_R_DRBG_ALREADY_INITIALIZED
);
888 if (drbg
->lock
== NULL
) {
889 if (drbg
->parent
!= NULL
&& drbg
->parent
->lock
== NULL
) {
890 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
891 RAND_R_PARENT_LOCKING_NOT_ENABLED
);
895 drbg
->lock
= CRYPTO_THREAD_lock_new();
896 if (drbg
->lock
== NULL
) {
897 RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING
,
898 RAND_R_FAILED_TO_CREATE_LOCK
);
907 * Get and set the EXDATA
909 int RAND_DRBG_set_ex_data(RAND_DRBG
*drbg
, int idx
, void *arg
)
911 return CRYPTO_set_ex_data(&drbg
->ex_data
, idx
, arg
);
914 void *RAND_DRBG_get_ex_data(const RAND_DRBG
*drbg
, int idx
)
916 return CRYPTO_get_ex_data(&drbg
->ex_data
, idx
);
921 * The following functions provide a RAND_METHOD that works on the
922 * global DRBG. They lock.
926 * Allocates a new global DRBG on the secure heap (if enabled) and
927 * initializes it with default settings.
929 * Returns a pointer to the new DRBG instance on success, NULL on failure.
931 static RAND_DRBG
*drbg_setup(RAND_DRBG
*parent
, int drbg_type
)
935 drbg
= RAND_DRBG_secure_new(rand_drbg_type
[drbg_type
],
936 rand_drbg_flags
[drbg_type
], parent
);
940 /* Only the master DRBG needs to have a lock */
941 if (parent
== NULL
&& rand_drbg_enable_locking(drbg
) == 0)
944 /* enable seed propagation */
945 drbg
->reseed_prop_counter
= 1;
948 * Ignore instantiation error to support just-in-time instantiation.
950 * The state of the drbg will be checked in RAND_DRBG_generate() and
951 * an automatic recovery is attempted.
953 (void)RAND_DRBG_instantiate(drbg
,
954 (const unsigned char *) ossl_pers_string
,
955 sizeof(ossl_pers_string
) - 1);
959 RAND_DRBG_free(drbg
);
964 * Initialize the global DRBGs on first use.
965 * Returns 1 on success, 0 on failure.
967 DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init
)
970 * ensure that libcrypto is initialized, otherwise the
971 * DRBG locks are not cleaned up properly
973 if (!OPENSSL_init_crypto(0, NULL
))
976 if (!CRYPTO_THREAD_init_local(&private_drbg
, NULL
))
979 if (!CRYPTO_THREAD_init_local(&public_drbg
, NULL
))
982 master_drbg
= drbg_setup(NULL
, RAND_DRBG_TYPE_MASTER
);
983 if (master_drbg
== NULL
)
989 CRYPTO_THREAD_cleanup_local(&public_drbg
);
991 CRYPTO_THREAD_cleanup_local(&private_drbg
);
995 /* Clean up the global DRBGs before exit */
996 void rand_drbg_cleanup_int(void)
998 if (master_drbg
!= NULL
) {
999 RAND_DRBG_free(master_drbg
);
1002 CRYPTO_THREAD_cleanup_local(&private_drbg
);
1003 CRYPTO_THREAD_cleanup_local(&public_drbg
);
1007 void drbg_delete_thread_state(void)
1011 drbg
= CRYPTO_THREAD_get_local(&public_drbg
);
1012 CRYPTO_THREAD_set_local(&public_drbg
, NULL
);
1013 RAND_DRBG_free(drbg
);
1015 drbg
= CRYPTO_THREAD_get_local(&private_drbg
);
1016 CRYPTO_THREAD_set_local(&private_drbg
, NULL
);
1017 RAND_DRBG_free(drbg
);
1020 /* Implements the default OpenSSL RAND_bytes() method */
1021 static int drbg_bytes(unsigned char *out
, int count
)
1024 RAND_DRBG
*drbg
= RAND_DRBG_get0_public();
1029 ret
= RAND_DRBG_bytes(drbg
, out
, count
);
1034 /* Implements the default OpenSSL RAND_add() method */
1035 static int drbg_add(const void *buf
, int num
, double randomness
)
1038 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1043 if (num
< 0 || randomness
< 0.0)
1046 if (randomness
> (double)RAND_DRBG_STRENGTH
) {
1048 * The purpose of this check is to bound |randomness| by a
1049 * relatively small value in order to prevent an integer
1050 * overflow when multiplying by 8 in the rand_drbg_restart()
1051 * call below. Note that randomness is measured in bytes,
1052 * not bits, so this value corresponds to eight times the
1053 * security strength.
1055 randomness
= (double)RAND_DRBG_STRENGTH
;
1058 rand_drbg_lock(drbg
);
1059 ret
= rand_drbg_restart(drbg
, buf
,
1060 (size_t)(unsigned int)num
,
1061 (size_t)(8*randomness
));
1062 rand_drbg_unlock(drbg
);
1067 /* Implements the default OpenSSL RAND_seed() method */
1068 static int drbg_seed(const void *buf
, int num
)
1070 return drbg_add(buf
, num
, num
);
1073 /* Implements the default OpenSSL RAND_status() method */
1074 static int drbg_status(void)
1077 RAND_DRBG
*drbg
= RAND_DRBG_get0_master();
1082 rand_drbg_lock(drbg
);
1083 ret
= drbg
->state
== DRBG_READY
? 1 : 0;
1084 rand_drbg_unlock(drbg
);
1089 * Get the master DRBG.
1090 * Returns pointer to the DRBG on success, NULL on failure.
1093 RAND_DRBG
*RAND_DRBG_get0_master(void)
1095 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1102 * Get the public DRBG.
1103 * Returns pointer to the DRBG on success, NULL on failure.
1105 RAND_DRBG
*RAND_DRBG_get0_public(void)
1109 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1112 drbg
= CRYPTO_THREAD_get_local(&public_drbg
);
1114 if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
))
1116 drbg
= drbg_setup(master_drbg
, RAND_DRBG_TYPE_PUBLIC
);
1117 CRYPTO_THREAD_set_local(&public_drbg
, drbg
);
1123 * Get the private DRBG.
1124 * Returns pointer to the DRBG on success, NULL on failure.
1126 RAND_DRBG
*RAND_DRBG_get0_private(void)
1130 if (!RUN_ONCE(&rand_drbg_init
, do_rand_drbg_init
))
1133 drbg
= CRYPTO_THREAD_get_local(&private_drbg
);
1135 if (!ossl_init_thread_start(OPENSSL_INIT_THREAD_RAND
))
1137 drbg
= drbg_setup(master_drbg
, RAND_DRBG_TYPE_PRIVATE
);
1138 CRYPTO_THREAD_set_local(&private_drbg
, drbg
);
1143 RAND_METHOD rand_meth
= {
1152 RAND_METHOD
*RAND_OpenSSL(void)